Thoracentesis apparatus



Nov. 11, 1969 A. M. GOLDBERG 3,477,437

THORACENTESIS APPARATUS Filed June :50, 1967 FIG.

INVENTOR All A II. 60103576 odd/ 1 flTTORA/EY United States Patent3,477,437 THORACENTESIS APPARATUS Allan M. Goldberg, Sepulveda, Califi,assignor, by mesne assignments, to American Hospital Supply Corporation,a corporation of Illinois Filed June 30, 1967, Ser. No. 650,370 Int. Cl.A61b 17/34; A61m 25/00 US. Cl. 128-347 7 Claims ABSTRACT OF THEDISCLOSURE This invention relates to thoracentesis apparatus normallyused to remove unwanted liquid from a patients lung cavity.

A thoracentesis procedure involves entering a patients lung cavity witha hypodermic needle on an end of a hypodermic syringe. A doctor pushes apointed end of the needle into the patients back until it protrudesslightly into the patients pleural (lung) cavity. By using thehypodermic syringe and a valve arrangement between the syringe andneedle, he can suck out the unwanted liquid. The system is airtight soliquid surrounding the lung can be pumped out without letting air enterthe lung cavity where it could cause the lung to collapse.

One of the problems with thoracentesis apparatus has been concentratedin the needle. The pointed end of the needles cannula cannot protrudetoo far into the lung cavity or the cannula might rip into the lung asit swings back and forth as the patient breathes. Thus, the doctor hadto be extremely careful to kep the cannula inserted to just the properdepth. This was difiicult, particularly since the doctor had tolongitudinally push and pull on the syringes plunger to pump out theliquid. As a makeshift precaution against shoving the cannula into thepatient too far, some doctors clamped a hemostat around the cannulaafter he found the proper depth.

There were disadvantages to using a hemostat in this manner. First, ahemostat is quite heavy and when it is hanging on a needle inserted intothe patient, it could aggravate the patients pain. Secondly, a hemostatis an expensive instrument and cannot be economically provided in aone-time-use disposable kit or tray comprised solely of disposableitems. Also, if the hemostat jaws were firmly clamped on a thin-walledmetal cannula they might crush the cannula.

To overcome these disadvantages in the hemostate clamped onto thecannula arrangement, I have invented a simple disposable clamp that fitsonto the cannula of a thoracentesis apparatus after its pointed cannulaend has been inserted into a patient. My invention can be betterunderstood with reference to the attached drawings, in which:

FIGURE 1 is a side elevational view of the thoracentesis apparatusshowing the cannula inserted into the patients pleural cavity;

FIGURE 2 is an enlarged view of my disposable depth gauge attached to acannula of the apparatus; and

FIGURE 3 is a cross-sectional view of the disposable depth gauge andcannula.

Turning now to the drawings, the thoracentesis apparatus includes ahypodermic needle 1 with a cannula 2 and 3,471,437 Patented Nov. 11,1969 a hub 3 attached to one end of the cannula. A pointed opposite end4 of the cannula penetrates into a patients pleural cavity 5 and thiscannula has a bore 13 adapted to carry out liquid 6 surrounding lung 7.

This liquid is sucked out by a hypodermic syringe 9 which is connectedto needle 1 through a valve 10. This valve has at least three ports andone of the ports connects to discharge tube 11. The doctor removesliquid 6 by pulling the syringes plunger rearwardly to fill the syringewith liquid 6. Next, he turns valve 10 so the syringe 9 and dischargetube 11 are connected. As he pushes forward on the plunger, he expelsthe liquid through discharge tube 11. Now, by turning valve 10 so thesyringe 9 and cannula 2 are connected, he can again fill syringe 9 withliquid 6. This cycle is repeated until the doctor has sufiicient liquidremoved from pleural cavity 5.

As can be seen, the doctor is longitudinally pushing and pulling on thesyringe plunger through this cycle. If he is not extremely careful hemight push cannula 2 too far into the patients lung cavity where itcould injure lung 7.

To avoid this, I have provided an open wound metal coil spring 8 whichfirmly wedges onto the cannulas smooth outer surface. This coil springcan be attached to the cannula after the cannula is inserted into thepatient. If the depth setting has to be adjusted, the doctor canlongitudinally slide the coil spring 8 along the cannula to make theadjustment.

The coil spring in its relaxed condition as shownin FIGURE 3 hasadjacent coils separated by a distance a, that is .005 inch to .025 inchless than the cannulas outer diameter. As the interference between theadjacent coils and the cannula is small, the wire of the relativelystiff coil spring 8 does not crush the thin wall of the cannula. Thewire in the coil spring has a diameter of between .040 inch and .080inch. The thin Wall of the cannula is between .005 inch and .020 inch.The coil spring is made of a wire which has a diameter at least one halfas large as the cannulas outer diameter so that adjacent coils presentrounded surfaces that can easily Wedge onto the cannulas rounded outersurface 15.

In the above specification and drawings, I rave used a specificembodiment to illustrate my invention. It is understood that personsskilled in the art can make certain modifications to this embodimentwithout departing from the spirit and scope of this invention.

I claim:

1. In an apparatus adapted to extract liquid from a patients body, theimprovement of: a needle which includes an elongated hollow cannula witha puncturing point on one end and an enlarged hub on an opposite end,said cannula having a smooth constant diameter outer surface extendingbetween its pointed end and its hub; and an open wound coil springclipped onto the smooth outer surface of the cannula between the pointedend of the cannula and the enlarged hub, said coil spring extendinglaterally from the cannula and forming a depth limit stop that can beattached to and longitudinally adjusted along the cannulas length aftera portion of the cannula adjacent its pointed end has been inserted intoa patient.

2. An improvement in the apparatus as set forth in claim 1 wherein thecannula has a thin metal wall surrounding a bore through the cannula,and wherein the open wound coil spring is formed of a metal wiresubstantially thicker than said cannula wall.

3. An improvement in the apparatus as set forth in claim 2 wherein thecannula wall is between .005 inch and .020 inch and the coil spring isof a metal wire that has a thickness between .040 inch and .080 inch.

4. An improvement in the apparatus as set forth in claim 1 wherein theopen wound coil spring has a distance between two adjacent coils intheir relaxed unstretched condition that is .005 inch to 0.25 inch lessthan the cannulas outside diameter, which two coils can grippinglyengage the cannulas outer surface without crushing the cannula.

5. An improvement in the apparatus as set forth in claim 1 wherein theopen wound coil spring is formed of metal wire with a roundcross-section which has a diameter at least One half as large as thecannulas outside diameter so as to present opposed rounded surfaces onadjacent coils between which the cannulas rounded outer surface canwedge.

6. Thoracentesis apparatus adapted to extract liquid from a pleuralcavity of a patient, said apparatus comprising: a hypodermic syringe; avalve having at least three ports, one port connected to a forward endof the syringe; a discharge tube connected to a second port of thevalve; a hypodermic needle connected to a third port; said hypodermicneedle including a hollow metal cannula with a wall surrounding acannula bore that is in axial alignment with said hypodermic syringe,said cannula having a smooth constant diameter outer surface thatextends between a pointed puncture point at a 25 forward end of thecannula and an enlarged hub secured to an opposite rearward end of thecannula, said hub attaching the hypodermic needle to the third port ofthe valve; and an elastic op'en wound coil spring clipped onto thecannulas smooth outer surface between the pointed end of the cannula andthe enlarged hub, said '4 coil spring extending laterally from thecannula and forming a depth limit stop that can be attached to andlongitudinally adjusted along the cannulas length after a portion of thecannula adjacent its pointed end has been inserted into a patient, saidopen wound coil spring having two adjacent coils that have a distancebetween them which is .005 inch to .025 inch less than the cannulasoutside diameter, whereby the two coils can grippingly engage thecannula without crushing the cannula.

7. Thoracentesis apparatus as set forth in claim 6 wherein the openwound coil spring is formed of metal wire with a round cross-sectionwhich has a diameter at least one half as large as the cannulas outsidediameter so as to present opposed rounded surfaces on the two adjacentcoils between which the cannulas rounded outer surface can wedge.

References Cited UNITED STATES PATENTS 20 1,43 6,707 11/ 1922 Gaschke12822l 2,001,638 5/1935 TornSjO 128-347 2,338,800 1/1944 Burke 128--215FOREIGN PATENTS 86,474 11/ 1895 Germany.

3 us. 01. X.R.

